Muffler



Jan. 26, 1932. J. w. VAN DYKE- 1,842,921

MUFFLER Filed Aug. 14. 1950 Patented Jan. 26, 1932 UNITED STATES JOHN W. VAN DYKE, OF PHILADELPHIA, PENNSYLVANIA imFrLEa Application led August 14, 1930.i Serial No. 475,146.

The present invention relates to an improved device for eliminating or damping the sound carried by exhaust gases and is particularly adapted for the muiiiing of sound carried by exhaust gases from internal combastion engines and the like.

In the mufliing art the ideal device is one which will completely deaden the sounds. issuing with exhaust gases, and at the same tune will offer the least possible resistance to the passage of the gases therethrough. From a practical standpoint it is desirable to produce a device of this type which is compact, inexpensive, and capable of extended use.

The common types of silencing devices usually consist of a cylindrical casing located at the outlet of the gas exhaust line, and forming an expansion chamber into which the exhaust gases pass. -In the expansion chamber is generally mounted a number of balliing members of one kind or another to diffuse the gases and cause them to flow in as nearly a constant and even stream as possible. rlh'e object of my invention is to provide a silencing device improved in structure and more efficient in operation than devices of the type heretofore known. This and other objects will appear from the following description of my invention.

I have found that a peculiar degree of efficiency in eliminating or damping the sound carried by exhaust gases may be attained by delecting the sound carrying gases by means of members of a twisted nature. My invention may be applied to the silencing of sound bearing gases from any source, for instance, exhaust steam. It has, however, particular utility in silencing the exhaust gases of internal combustion engines. As will be readily seen by one skilled in the art from the description to follow, my invention may be embodied in various structures and therefore it is not my intention to specifically limit its application.

My invention will be further explained in connection with the accompanying drawings and description of a preferred form.

Fig. 1 is a longitudinal section through the center of the silencing device;

' Fig. 2 is an enlarged section of a typical baille assembly; and

Fig. 3 is a transverse section taken on line 3 3 of Fig. 1.

In the drawings, casing. A head assembly 2 is secured to the inlet end of casing 1, and carries the gas inlet pipe 3. The construction of the head and inlet portions may be of any convenient type. The outlet end 4 of casing 1 is unobstructed. In some instances it may be desirable to provide a more restricted outlet, such as a continuation of the exhaust pipe which transfers the exhaust gases from the motor or other source to the inlet pipe 3. Surrounding the casing 1 there is provided a jacket 5, secured in spaced relation to the casing 1 in any snitable manner, for example, to a supporting member at the outlet end of the casing and to the shoulder of a conventional device 6 by means of which the device as a whole is secured to a stationary support. Other suitable strcture may be substituted for the structure above described.

The structure within the expansion chaniber formed by the casing 1 is particularly adapted to dissipate the sound carrying gases to eifect a mufling or silencing of the sound and at the same time to smooth out the gas pulsations, thereby causing a more even flow of gases from the outlet 4. The expansion chamber is divided into a number of separate compartments by the partitions 10 mounted transversely within the casing 1. These partitions have apertures 11 and may be spaced at equal or unequal intervals lengthwise of the casing. Ordinarily, the apertures 11 of the partitions 10 are of a diameter somewhat larger than that of the inlet 3. It will be understood, however, that the size of these apertures depends upon such factors as the particular exhaust gas being silenced, the size of the expansion chamber, number of partitions, rate at which gas it to be passed through the device, etc.

On the inlet side of each partition and surrounding the aperture therein there is mounted a basket-like battling structure. This structure comprises a. plurality of gas deflectlng members 14 which extend longitudinally 1 represents a cylindrical I' of the expansion chamber and are twisted lengthwise to give them a spiral or helical contour. These members, which for example, may be. fiat metal bands having a twist of approximately 180o, are secured at one. end to a circular dished plate 15, the concave slde of which faces the inlet end of casing l. The gas deflecting members 14 are preferably arianged as an annulus in closely spaced relation in order to insure an adequate deiectmg action upon the exhaust gases.

rl`he outlet end of the last baffle compartment is followed by an outlet chamber formed by the partition 2O which has a central aperture 21 surrounded on the outlet side by the sleeve 22, which directs the issuing gases toward the concave face of the dished plate 23 held in spaced relation to said sleeve. It is to be noted that this particular type of outlet chamber is not an essential part of my invention, and may be replaced by other conventional outlets.

As to the operation of my silencing device, the sound carrying gases entering at 3, strike the concave surface of the first baille plate 15, and c pand outwardly. The expanded vases nex.. pass through the annular space lbetween the plate 1o and the casing 1, and then pass the spirally twisted gas deiecting members 14 in a direction at an angle to the axes of the twisted gas deflecting members, the twisted members thereby exerting a marked silencing and smoothing out or dissipatin effect thereupon. After passing the gas de ecting members in the first compartment, the dlffused gases pass through the aperture 11 of the first partition l() and expand into the next adjacent bafiie compartment, contact with the'second bafile plate 15, then encounter the second group of gas defleeting members 14, and so on through the several compartments of the device. The number of baffle compartments may vary according to the particular muiiiing problem at hand. Gases issuing from the last bafiie chamber pass through the opening 21, then expand, and are accorded a final diffusion by the plate 23 before leaving the chamber through the outlet 4.

As before stated, my invention may be embodied in many modifications, and the foregoing description of a specific structure is merely for purposes of illustration.

What I claim is:

1. In a sound damping device for exhaust gases, a casing forming a passage for the gases, and a plurality of spirally twisted gas deflecting members mounted within said casing at an angle to the path of fiow of the gases. said members being spaced transversely one from another, whereby gases may pass through the space so provided and be diffused as a result of coming into contact with the surfaces of said members.

2. In a sound damping device for exhaust gases, a casing forming a.l passage for the gases, and a plurality of spirally twisted gas deflecting members mounted within said casing at an angle to the path of flow of the gases, said members being spaced transverse.- ly one from another throughout their lengths, whereby gases may pass through the space so provided, and upon impinging upon the surfaces of said members will be caused to rotate relative tothe axes of the members and be diffused due to the bathing action of said members.

3. In a sound damping device for exhaust gases, a easing forming a passage for the gases, a plurality of twisted gas deflecting members mounted within said casing at an angle substantially transverse to the path of flow of the gases, each of said members being spaced from another transversely of its length and having a twist lengthwise of 180, whereby gases may pass through the space so provided, and, upon impinging upon the surfaces of said members, be caused to rotate relative t-o thel axes of the members and to be diffused due to the bafiiing action of' said members.

4. In a sound damping device for exhaust gases, a casing forming a passage for the gases, partitions mounted within said casing dividing it into a series of compartments, each partition having at least one aperture, at least one of said compartments having twisted gas deflecting members mounted therein, spaced from each other transversely of their lengths and arranged at an angle to the path of flow of the gases, so that the gases may pass through the spaces therebetween and whereby the gases upon coming into contact with the members are put in helical motion relative to the axes of the members, and are diused due to the bafiiing action of said members.

5. A sound damping device for exhaust gases comprising a casing forming a passage for the gases, a plurailty of partitions mounted within said casing, each partition having at least one aperture therein, a plurality of twisted gas deflecting members mounted within said casing in the path of flow of the gases and extending from said partitions lengthwise of the casing,` circular deflecting discs mounted transversely of the casing at the ends of the twisted gas deflecting members away from the partitions, said deflecting discs being smaller in diameter than the casing so that annular passages are provided between the deflecting discs and the casing.

G. A sound damping device for exhaust gases comprising a casing forming a passage for the gases, a plurality of partitions mounted within said casing to form a series of compartments, each partition having at least one aperture therein, a plurailty of twisted gas deflecting members mounted within at least one of said compartments around the aper- 'ture in a partition and transversely of the path of flow of the gases.

7. A sound damping device for exhaust gases comprising a casing forming a passage for the gases, a plurality of partitions mounted transversely within said casing to form a series of compartments, each partition having a central aperture, a plurality of twisted gas delecting members surrounding the apertures in said partitions, and arranged transverse of the pathv of flow of the gases.

8. A sound damping device for exhaust gases comprises a casing adapted to form a passage for the gases, a plurality of partitions mounted transversely within said casing to form a series of compartments, each partition having a center aperture, a plurality'of twisted gas deflecting members mounted within said compartments longitudinally of said easing and transverse of the path of low of the gases, said members being spaced transversely one from another so that gases may pass through the space between them.

9. A sound damping device for exhaust gases comprising a casing adapted to form a passage for the gases, a plurality of partitions mounted transversely of said casing to form a series of compartments, each partition having a central aperture, a plurality of gas deflecting members mounted within said compartments, around said apertures and longitudinally of the casing, said defiecting members being twisted lengthwise substanially 180 and being arranged in spaced relation to each other and transverse to the path of fiow of the gases, so that gases may pass through the space between them.

10. A sound damping device for exhaust gases, comprising a easing adapted to form a passage for the gases, a plurality of annular partitions mounted transversely within said casing to form' a plurality of compartments, each partition having a central aperture, a plurality of twisted gas deflecting members mounted within said compartments, longitudinally of the casing and around the aforesaid central apertures, and concave delecting elements of diameter less than that of the casing mounted at'the ends of the gas deflecting members away from the annular partitions, said concave deflecting elements forming annular passageways with the walls of the casing.

l1. In a sound damping device for exhaust gases, a casing forming a passage for the gases, and means disposed therein which serve both to give the gas a spiral motion and to diffuse the gas, sai-d means comprising twisted members arranged at an angle to the path of flow of the gases and spaced transversely from each other so that gases may pass through the space between them.

12. In a sound damping device for exhaust gases, a casing forming a passage for gases and an annulus ol' spiral ly twisted gas deflectnulus of longitudinally twisted gas deflecting i members mounted therein, said annulus of defleeting members encircling the aperture in the partition of the compartment, and the longitudinally twisted members of said annulus being so disposed diagonally to the direction of the path of How of the gases therethrough, that the gases in theirpassage through said annulus are put into rotary motion and diffused by the twisted members of the annulus. 14. A sound damping device for exhaust gases comprising a casing adapted to form a passage for the gases, a plurality of annular partitions mounted transversely within said casing to form a plurality of compartments, an annulus of twisted gas deiiecting members mounted within said compartments, longitudinally of the casing and around each of the central apertures of said annular partitions, and deflecting elements of diameter less than that of the casing mounted at theI ends of the gas delecting members away from the annular partitions, said deflecting elements forming annular passageavziys with the walls of the casing.

In testimony whereof I affix my signature.

JOI-IN W. VAN DYKE.

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